via=through
duct=to lead


A viaduct is a bridge composed of several small spans for crossing a valley or a gorge.

The term viaduct is derived from the Latin via for road and ducere to lead something. 

However, the ancient Romans did not use that term per se; it is a modern derivation from an analogy with aqueduct.

Like the Roman aqueducts, many early viaducts comprised a series of arches of roughly equal length. Viaducts may span land or water or both.